ABCD2 Score
Select one option per criterion. Maximum score = 7.
A — Age
Patient's age at time of TIA
B — Blood Pressure
BP at first assessment after TIA (even if on antihypertensives)
C — Clinical Features
Predominant presenting symptom of the TIA episode
D — Duration of Symptoms
Total duration of TIA symptoms from onset to complete resolution
D — Diabetes
Known diabetes mellitus (on treatment or previously diagnosed)
ABCD2 Score (max 7)
0
—
ABCD2 Score (max 7)
ABCD2 Score
—
/ 7
2-Day Stroke Risk
—
%
7-Day Stroke Risk
—
%
ABCD2 Score — Stroke Risk Reference
| Score | Risk Category | 2-Day Stroke Risk | 7-Day Stroke Risk | Action |
|---|---|---|---|---|
| 0–3 | Low | ~1% | ~1.2% | Urgent outpatient clinic within 24h |
| 4–5 | Moderate | ~4% | ~5.9% | Same-day specialist review. Do not discharge without assessment |
| 6–7 | High | ~8% | ~11.7% | Admission recommended. Immediate investigation |
Urgent Investigation for ALL TIA Patients (AHA/ASA 2021)
The ABCD2 score identifies risk but all TIA patients warrant urgent investigation regardless of score. The EXPRESS and SOS-TIA trials showed that rapid same-day treatment reduced 90-day stroke risk by 80%.
- Brain imaging: MRI with DWI within 24h (preferred) — identifies acute infarct in ~50% of TIAs confirming stroke diagnosis. CT head if MRI unavailable or contraindicated
- Vascular imaging: CT angiography or carotid duplex — urgent if anterior circulation TIA. Carotid stenosis >50% = surgery within 2 weeks (CEA or stenting)
- Cardiac monitoring: ECG, 24-72h Holter (or prolonged monitoring if cryptogenic) — AF found in 10–15% of TIA patients
- Bloods: FBC, ESR, glucose, lipids, HbA1c, coagulation screen
- Echocardiography: If cardioembolic source suspected (AF, valvular disease, young patient)
Immediate Secondary Prevention — Start Within Hours
- Dual antiplatelet therapy (DAPT): Aspirin 300 mg loading dose IMMEDIATELY + Clopidogrel 300 mg loading dose. Then aspirin 75 mg + clopidogrel 75 mg daily for 21 days (POINT trial / CHANCE trial). After 21 days: aspirin 75 mg alone long-term
- Statin: Start high-intensity statin immediately — atorvastatin 40–80 mg OD. Target LDL <1.8 mmol/L (70 mg/dL)
- Blood pressure: If SBP >140 mmHg, start/optimise antihypertensive within 24h. Target <130/80 mmHg long-term. Do not lower aggressively in acute phase
- Anticoagulation: If AF confirmed — start DOAC after ruling out haemorrhage on imaging. Do not give DAPT if anticoagulating
- No tPA: Thrombolytics are NOT recommended for TIA (symptoms fully resolved)
Limitations of ABCD2 Score
- ABCD2 does not replace clinical judgement — even a score of 0–3 does not make TIA "safe" to discharge without investigation
- ABCD2 was not designed to differentiate TIA from TIA mimics (hypoglycaemia, migraine aura, Todd's paresis, functional disorder)
- DWI-positive lesion on MRI is a better predictor of early stroke than ABCD2 score alone
- Crescendo TIA (≥2 TIAs in 1 week): very high risk regardless of ABCD2 score — treat as stroke emergency
Frequently Asked Questions
Related Calculators
⚠ Medical Disclaimer: ABCD2 score is a risk stratification tool — it does not replace urgent clinical assessment. All TIA patients require urgent specialist evaluation, neuroimaging, and vascular imaging regardless of score. Never use ABCD2 alone to justify discharge from the emergency department. If in doubt, admit.